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THE KEY ENERGY JUMP. "The role of energy and the energetic constraints that prokaryotic cell organization placed on evolutionary innovation in cell history has recently come to bear on endosymbiotic theory. Only cells that possessed mitochondria had the bioenergetic means to attain eukaryotic cell complexity, which is why there are no true intermediates in the prokaryote-to-eukaryote transition." https://lnkd.in/d8-2n7b View in LinkedIn

ONGOING ENDOSYMBIOTIC EVENTS. "In insects mutualistic symbionts are often associated with nutritional aspects where hosts build obligate relationships with endosymbionts. Most mutualists are in an evolutionary long-lasting host–symbiont relationship and have evolved complete vertical transmission. Among those the most specific relationships have evolved as intracellular vertical transmission, very similar to mitochondria or chloroplasts." https://lnkd.in/dChz5SR View in LinkedIn

SYMBIONTS DEFINE MATE SELECTION. "In sexual reproduction different types of symbiotic relationships between insects and microbes have become established. For example, some bacteria have evolved almost exclusive vertical transmission and even define the compatibility of insect mating partners. Many strictly sexually transmitted diseases have also been described in insects." https://lnkd.in/dChz5SR View in LinkedIn

RARER MALE TRANSMISSION. "This conventional knowledge is countered by our discovery of intrasperm vertical transmission of nuclear-targeting bacterial symbiont (Rickettsia) in an insect (leafhopper Nephotettix cincticeps), which potentially erodes the nuclear-cytoplasmic conflict that governs the majority of endosymbiotic associations." https://lnkd.in/dzMQrDi View in LinkedIn

OPEN VERSUS CLOSED SYMBIOSIS. "All animals are colonized by microorganisms that promote the health and fitness of their animal host. Many associations are open, meaning that microorganisms can be gained by the animal from external sources and are shed from the animal back to the environment, but other associations are closed with obligate vertical transmission, generally from mother to offspring." https://lnkd.in/dzMQrDi View in LinkedIn

MATERNAL TRANSMISSION. "Diverse organisms are commonly associated with bacterial endosymbionts, which often affect hosts’ biology and phenotypes in a variety of ways. The majority of these symbionts are generally present in the host cell cytoplasm and maternally transmitted through host generations." https://lnkd.in/dzMQrDi View in LinkedIn

COOPERATIVE STRATEGY. "Viruses can co-operate, that is they interact to build groups that invade host genomes and even compete as a group for limited resources such as host genomes. This leads to an extraordinary effective result and a key behavioral motif that is able to integrate a persistent lifestyle into cellular host organisms, the ‘‘addiction’’ modules: former competing viral groups are counterbalancing each other together with the host immune system." https://lnkd.in/eWydwab View in LinkedIn

INCOMPARABLY MORE EXTENSIVE. "All these lines of evidence and reasoning suggest that the principal classes of prokaryotic viruses, including positive-strand RNA viruses, retroid elements, and several groups of DNA viruses, emerged within the primordial genetic pool where mixing and matching of diverse genetic elements was incomparably more extensive than it is in any modern biological community." https://lnkd.in/dHhQ6QH View in LinkedIn

NO COMMON ROOT. "Comparative genomics provides no evidence of a monophyletic origin of all viruses. Many virus groups simply share no common genes, effectively, ruling out any conventional notion of common origin. When applied to viruses, the notion of "common genes" is not a simple one because commonality is not necessarily limited to clear-cut orthologous relationships between genes that translate into highly significant sequence similarity." https://lnkd.in/dHhQ6QH View in LinkedIn

FEW NEEDED. "Importantly, a key feature of this viral lifestyle is that only few need to remain as functional agents, such as mammalian endogenous retroviruses needed for in the syncytia, which regulates mammalian pregnancy. Here, a much larger number of retroviral-derived code (LTRs) are providing the regulatory network of the placenta." https://lnkd.in/eWydwab View in LinkedIn